The present invention relates to a filter system for use in enclosure devices. More particularly, the present invention relates to a micro-porous filter system for venting a build up of explosive/flammable hydrogen gas out of an electrical enclosure, particularly, a lighting fixture.
Many electrical enclosures, including some lighting fixtures, have a charger circuit and an emergency, back up or standby battery that produces hydrogen gas when charged. This build up of hydrogen gas may result in an inadvertent explosion or fire during opening of the enclosure.
The charging process of rechargeable batteries, such as nickel cadmium and other rechargeable batteries, can cause the electrolyte liquid chemical content of the batteries to break down and release hydrogen gas molecules into the atmosphere. Since hydrogen gas is explosive and flammable at a 1% concentration, any build up in an enclosure device is potentially hazardous.
Conventional systems for venting gas out of such enclosures have been problematic, in that any venting of the gas can result in the filter allowing liquid, or more specifically water, and other contaminants to pass therethrough. This contamination is due to the conventional venting systems generally employing a pressure release valve or mechanism. Many electrical enclosures need to be able to vent gases and still maintain a xe2x80x9cwet locationxe2x80x9d or a xe2x80x9chose downxe2x80x9d ability to satisfy important application requirements.
Conventional filter systems are disclosed in U.S. Pat. No. 707,318 to Geyer et al.; U.S. Pat. No. 2,980,204 to Jordan; U.S. Pat. No. 3,898,063 to Gazan; U.S. Pat. No. 4,171,209 to Brown; U.S. Pat. No. 4,405,974 to Quiogue; U.S. Pat. No. 4,422,861 to Dusza; and U.S. Pat. No. 5,891,223 to Shaw et al.
Accordingly, an object of the present invention is to provide a gas filter assembly that can meet a xe2x80x9cwet locationxe2x80x9d or a xe2x80x9chose downxe2x80x9d requirements.
Another object of the present invention is to provide a gas filter assembly that allows gas to pass into and out of an enclosure, while prohibiting passage of liquid and solid contaminants.
A further object of the present invention is to provide a gas filter assembly that allows gas to pass into and out of an enclosure, while prohibiting passage of liquids and solid contaminants, without the use of a valve or similar mechanism.
Yet another object of the present invention is to provide a gas filter assembly that reduces the possibility of an explosion or fire during the opening of an electrical enclosure.
Still another object of the present invention is to provide a gas filter assembly that is cost effective and easy to produce, install and maintain.
The foregoing objects are basically obtained by a gas filter assembly having a fitting with a first portion, a second portion and a housing coupling. A filter member having a peripheral portion is positioned between the first portion and the second portion. An adhesive is disposed on the peripheral portion, securing the filter member to at least one of the first portion and the second portion.
The foregoing objects are also obtained by an electrical enclosure having a fixture housing with an aperture therein. A filter member is positioned adjacent the aperture. An adhesive is disposed on a peripheral portion of the filter member and secures the filter member to the fixture housing adjacent the aperture.
By forming the gas assembly as described, the assembly will allow gas, specifically hydrogen, to vent out of an electrical enclosure, and ambient air to enter the enclosure and will prohibit liquids and other contaminants, specifically water, from passing therethrough. This structure allows the enclosure to be hosed down or be exposed to water, and simultaneously prevents possible explosions or fires.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.